摘要 |
<p>According to exemplary embodiments of the present invention, non-uniform helical antennas are described for use in two or more frequency hyperbands. For example, non-uniform helical antennas can be designed according to the present invention for usage in portable terminals capable of operating both at 800 MHz and at 1900 MHz. Tuning to both resonance frequencies can be accomplished by varying parameters of the helical antennas including, for example, the pitch angle, coil diameter, length and number and spacing of the coil turns.</p> |